Compression-seal for pistons



E. 1. BULLARD. COMPRESSION SEAL FOR PISTONS.

APPLICATION FILED OCT. 13, I920.

. Patented Aug. 23, 1921.

wh m;

I To all whom it mag concern:

' citizen, of the United States, residing at- Madison, in the county of Dane and State of "and low pressure, bu't the development of UNITEUSTATES" OFFICE,

' man J. Bunmnn, or p1 wrsconsm.

courREssIoN-smL ion PISTONS.'J

Be it known that I, EARL J. BUlll aA RD, a-

VVisconsi-n, have invented a certain new and useful Improvement in Compression-Seals a 7 the. movin for Pistons, of whichthe;following is a specification. f i 1 g This invention relates to tlfe cylinders of engines, pumps and-the like in which a reciprocating PlSlSOIllSQlIl use. The Object of the invention is toprovide at seal between piston and the cylinder wall, which is effective at all temperatures to prevent the escape of compressed gas air vapor orliquid confined by the piston within the i cylind er,'p a-st the piston'as it moves in'one direction and which prevents the pumping of oil by thepistoninto the compressionspace of the c linder.

The invent on consists in a particular packing ring and the use of that ringw'ith and without other ring combinations on the ,piston of" a--- cylinder ofthe class '''described which attains the foregoing objects. More particularly it consists m a device easily and cheaply made, efficient and satisfactory in use and not liable to get. outof order, and; also inj'many features and details of con-, struction herea er more fully-set forthin ends22 and 4 overlapping on a circumferwhich permits circumferential the s ecifi'eationand claims.

Re erring" w the drawings. in whichsimilarnumerals indicate the same parts throughoutthe several views, Figure 1 's a sectional ,view' of the cylinderof an engine of ,the combustion type having a vertically reciprocatable piston, shown partiall in section therein, the same equip p Wit 40' :Fig. '2 is 'a perspective view 0 the device of thisinvention in its two'zfmost' important forms. -n

f an fordinary;pisto n ring equipped with one of the rin s of this invention.

ig. 3 is a perspective view of a'plain ring Fig. 5 is a p erspectiveview of a spring constituting partof the mvention. I ig; 6 is a side view of the two endsof the ring of Fig. 3 separated onefrom the other.

'- From the earliest history ofthe use of a cylinder and reciprocating piston as a pump .or engine, packing rings have been used on the piston to prevent the passage of gas or Specification of Letters Patent. Patented A llg. 192 1. Application 'flled October 13,1920. Serial No. 416,685.

liquid more or less compressed, from one end of the piston to the other, the-earliest type being a leatheror felt w'a sher. which was good enough at atmospheric temperature .the modern high speed, high pressure and high temperature engine of the automobile and m craft artshas created an imperative demand for a perfect compression seal-between piston. and cylinder which has not, prior to this invention, been met ina 'practical way, though thousands have shot'at the mark.

The desired result is attained by -taking make theseal. of this invention. K

In carrying out this inventionthe' ring ring. seats 14 or 16 and contact the' inner cir-.

. the foregoing the ring of this invention to 50' 20 is provided of; suitable diameter to lie in p cumfe'rence of cylinder 12. The'ring is preferably made about one thirty secondof an inch thick.- It is eqliippedv with notched of'tlie body of the ring.

1- This ring may be of any sii table material having sufiicient elasticity sothat th rin will expand to the cylinder walls5- -1;Qopper or brass may be used. for the; purpose.

' Thisring is placed on the side ofthe ring seat 14 or 16 occupied by ring18 which" is farthest away from the combustion mm; ber 28, of the cylin'derj12. In theparticular case here illustrated the engine is. vertlcal with the combustion-space at'the topof the cylinder so :the ring 20 is placed'in each.

case below the ring '18. Whereas shown in connectionwithjthe upper ring 18 in'ring seat 14 of Fig.1 no other-parts are added the device works very well; the pressure'of gas or liquid in space 28 above ring 18 en- 1 20 to make an effective seal.

"gaging that ring and pressing down. on ring However, f the preferred construction is that shown in connection-with the lower ring.

18 in groove 16 of Fig. 1 in which the parts are exactly the same as before except that a supplemental spring ring 32 is interposed above ring 18 in the ring seat 16. In the particular case here illustrated ring 32 is exactly like ring 28 except that it is laterally sprung (the drawing being very much exaggerated) sufficiently so that when put in place as shown, it acts as a spring to force ring 18 down on ring 20.

It is important in assembling the parts to have the joints 34, 26, and 36 of the respective rings break joint with each other.

In the operation of the device the commercial ring 18 carries the load of scraping along the inner circumference of the cylinder in the ordinary manner and more or less effectively seals at all points thereon except at the joint 34 but the ring 20 being pressed at all points onto the side of ring seats 14 or 16 prevents the escape of compression between the ring 20 and the seat and being provided with the joint 26 prevents the passage of compressed gas or liquid in any direction. Inthe preferred constructions the spring ring 32 enforces this action.

In applying the mechanism to Worn en.-

-gines'which would ordinarily require new,

Having thus described my invention what I claim vas new and desire to secure by Letters Patent, is

1. In mechanism of, the class described, in combination with a piston having a circumferential ring seat of substantial width, a ring of any suitable construction occupying most of the width of the ring seat and a relatively thin ring having a circumferenl tial expansion joint, interposed between the metal having a circumferential expansion joint, interposed between the wide ring and the ring seat wall and held in place by the wider ring to make an effective compression seal, and a spring ring occupying the space between the other side of the wider ring and the ring seat.

In witness whereof I have hereunto sub-- scribed my name in the presence of two witnesses.

EARL J. BULLARD. Witnesses W. J. HANNUM, C. K. SwAFFoRn. 

